Custom Object - Field Size

Content

Hi all,

Here is a new one for me. I have a custom object, which contains quite a number of fields. I have a significant number of Text type fields, which had various sizes. Some with 50, other 100, other 255. I was trying to increase all of them to 255 and got the attached error. Has anyone bumped into this situation before? Is this a known limitation of the platform?

Thanks in advance.